1. A researcher collected a sample of data regarding the mean number of hours a person spends online performing work tasks during the current COVID-19 pandemic. A 95 % confidence level is computed with appears to be very broad. Explain what things the researcher could do to make the confidence interval narrower.

2. A pharmaceutical company scientist is testing whether the mean level of a toxin in a newlycreated children's medicine is less than 5mg, a level which could damage the children taking it.

a. If the test were conducted on a sample of 5,000 bottles, explain how the results could give significant results, but still make the company hesitant about making the medicine.

b. 5% is a very common significance level for significance tests, but it Is arbitrary. In this case explain what you might change the significance level to and why you would consider changing it.

3. A market researcher chooses at random from people entering a large upscale department store.One outcome of the study is a 95% confidence interval for the mean of "the highest price youwould pay for a handbag". Explainwhy this confidence interval does not give useful information about the population of all people also explain what information the 95% confidence interval does provide.